This invention relates to a fastening device and particularly relates to a fastening device for applying fastening elements to a structure.
Fastening elements, in particular those composed of plastic materials, have a broad field of application. For example, plastic fastening elements are used for fastening parts or components of motor vehicles to the body or frame of such vehicles, and can be of a variety of designs to suit the particular structural need.
Typically, the fastening element can be fastened or applied to a structure by means of a jointing tool, which can be supplied with individual fastening elements. The supplying of individual unconnected fastening elements to the jointing tool is a relatively expensive process. To provide a more efficient and less costly process of feeding the fastening elements to and through the jointing tool, and applying the elements to the structure, a system has been developed for linking successive fastening elements in the form of a supply belt. A system in which the fastening elements are linked to form a supply belt is disclosed in U.S. Pat. No. 5,478,051, which issued on Dec. 26, 1995, to Deiter Mauer.
The individual fastening elements are linked together in a proper spacial relationship to facilitate assembly thereof with the structure. The successive fastening elements are connected to form the belt and include guide elements on one or both sides of the fastening elements which are linked by monofilaments molded with the guide elements in a single stage of manufacture. The belt of the flexible fastening elements can be wound onto a drum and eventually transferred to the jointing tool. With the availability of the supply belt of fastening elements, the problems previously encountered when sorting and feeding individual elements to the tool have been eliminated.
Since the guide elements are identical and are, therefore, standardized regardless of the structure of the fastening elements, the advance and exact positioning of each fastening element is thus achieved. The linked fastening elements are feed through the jointing tool, where the lead fastening element is properly positioned adjacent the location of the structure at which the element is to be assembled. The lead fastening element is then separated from the linking guide elements and the monofilaments and assembled with the structure, whereafter the guide elements and the monofilaments are collected and transported to a recycling location.
With known jointing tools, fixed or stationary devices are used to apply fastening elements to a structure. The advantage of these stationary devices is that relatively large quantities of fastening elements can be stored in a drum. However, such known devices can only be used if the receiving structure can be brought to the device. With relatively complicated structures, the structures have to be appropriately handled and manipulated for the application of individual fastening elements which are not to be located in a given plane. Such handling of the structure is not always possible, as in the case of a motor vehicle body, for example. The known stationary device also has limitations in the application of fastening elements in the interior of a structure.
A prior fitting arrangement for applying a spring nut to a fastening peg projecting from a buffer rail is disclosed in German Patent No. DE 27 37 602 A1, which was published on Mar. 1, 1979. The fitting arrangement has a pistol-like housing. A working unit comprising a plunger actuated by compressed air for depressing the spring nut is arranged in the housing. The spring nuts are brought into a fitting position through a feed duct extending substantially perpendicularly to the direction of movement of the plunger. The feed duct is connected to a flat drum which acts as a magazine for the spring nuts. A coil of the spring nuts is arranged in the flat drum.
Another prior fitting arrangement for the application of nails is disclosed in German Patent No. DE 36 06 901, which was published on Sep. 10, 1987. The fitting arrangement comprises a opening in which a movable piston is located. A radial duct, substantially formed by a hollow profile, is formed with an orifice in which the piston is movable. Several nails are connected together by guide bushings which are located in the radial duct.
Also, German Patent No. DE 28 29 566, which was published on Jan. 25, 1979, discloses a device for applying fastening elements to a structure with a magazine for receiving fastening elements which are connected together in the form of a belt. The device comprises a conveyor unit which conveys each fastening into a predetermined fitting position. The device also comprises an automatically operating working unit with a rectilinearly reciprocation tool by means of which a fastening element can be applied from the fitting position onto a structure. The working unit is actuated by use of an actuating arrangement.
The magazine is designed in the form of a container or a bushing. The fastening elements are firstly are formed in a roll and arranged in the magazine which is designed as a bushing, for which purpose a press-fit lid has to be removed from the a body of the bushing. The roll, with a portion of the fastening elements, can then be inserted through an inlet orifice.
Due to the shape of the magazine and its position relative to the housing of the device, handling of the device is relatively complicated because the device is relatively bulky in design.